This paper develops an integrated economic model for the joint optimization of quality control parameters and a preventive maintenance policy using the cumulative sum (CUSUM) control chart and variable sampling interval fixed time sampling policy. To determine the in-control and out-of-control cost for both mean and variance, a Taguchi quadratic loss function and modified linear loss function are used, respectively. Imperfect preventive maintenance and minimal corrective maintenance policies were considered in developing the model, which determines the optimal values for significant process parameters to minimize the total expected cost per unit of time. A numerical example is used to test the model, which is followed by a sensitivity analysis. The integration of CUSUM mean and variance charts with the maintenance actions are proven successful to detect the slightest shift of the process. The findings reveal that among all the cost components, process failure due to external causes and equipment breakdown has a noteworthy attribute to the total costs of the optimized model. It is expected that top managers can utilize the suggested combined model to minimize the costs related to quality loss and maintenance policy and achieve economical advantages as well.

本文使用累积总和（CUSUM）控制图和可变采样间隔固定时间采样策略，开发了用于联合优化质量控制参数和预防性维护策略的集成经济模型。为了确定均值和方差的控制内和控制外成本，分别使用了Taguchi二次损失函数和修正的线性损失函数。在模型开发过程中考虑了不完善的预防性维护和最少的纠正性维护策略，该策略确定了重要工艺参数的最佳值，以使单位时间的总预期成本最小化。数值示例用于测试模型，然后进行敏感性分析。事实证明，将CUSUM均值和方差图与维护操作相集成可以成功地检测出过程中的任何微小变化。调查结果表明，在所有成本要素中，由于外部原因造成的过程故障和设备故障在优化模型的总成本中具有值得注意的属性。期望高级管理人员可以利用建议的组合模型来最大程度地减少与质量损失和维护策略相关的成本，并获得经济优势。